Sylvania



C. LE G. FORTESCUE.

CAM RECTIFIER.

APPLICATION FILED MAR. 30. 1914.

l 1 94,1 60. Patented Aug. 8, 1916.

WITNESSES: INVENTOR 7 I BY ATTORNEY UNITED STATES PATENT OFFICE.

CHARLES LE G. FORTESCUE, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TOWESTING- HOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OFPENN- SYLVANIA.

CAM-RECTIFIER.

Application filed March 30, 1914.

To all whom it may concern:

Be it known that 1, CHARLES Lu G. FOR; TESC-UE, a subject of the King ofGreat Britain, and a resident of Pittsburgh, in the county of Alleghenyand State of Pennsylvania, have invented a new and useful Improvement inCam-Rectifiers, of which the following is a specification.

My invention relates to apparatus for rectifying alternating current andparticularly to that type known as mechanical rectifiers.

The Object of my invention is to provide a simple, compact device of thecharacter described which shall have few working parts, be positive inaction, and readily adjustable.

Referring to the accompanying drawing, Figure 1 is a view, in frontelevation, of my rectifier; Fig. 2 is a View, in side elevation, of thesame; and Fig. 3 is a diagrammatic view of my rectifier and itscircuits.

Mounted upon a base 1, is an insulating member 2 carrying fixed contactmembers 3 and 4. Each of the contact members 3 and 4 comprises a springand a tip of some refractory material, such, for example, as carbon,platinum, tungsten or the like. Mounted on an oscillating carrier 5, isa double contact member 6 so placed as to oscillate between contactmembers 3 and 4. The contact member 6 is also provided with refractorytips which are preferably dissimilar to those pertaining to contactmembers 3 and 4, in order to prevent sticking. The member 5 is ofsubstantially Y-shape and is pivotally mounted on base member 1 at thepoint 7 and pro- .vided with two rollers 8 and 9. Embraced by the twoarms of the Y, in such position as to bear upon the rollers 8 and 9, isa cam member 10 that is driven by a synchronous motor 11. Current leadsextend from the two terminals 12 and 13 of an alternating current source14 to respective contact members 3 and 4. The contact member 6 isconnected to the middle point of the. source 14 through a conductinspring 15 that is connected with a fixed binding post 16 on theinsulating member 2. Inserted in the connection between the contactmember and the source 14, is the direct-current load of the rectifier,as, for example, a storage battery 17. The synchronous motor 11 isdriven from the alternating current source 14 by means of connections 18and is provided with direct current excitation from a separate source19. Obviously, the field winding Specification of Letters Yatent.

Patented Aug. 8, 1916.

Serial No. 828,209.

of motor 11 may be fed from battery 17, if found desirable.

Having thus described the construction of my rectifier, I w ll nowproceed to set forth the operation thereof.

Cam 1O, being driven in synchronism with the frequency of source 14 bymotor 11, will cause the member 5 to oscillate in synchronism and thuseffect contact between members 4 and 6 at such times as member 4 ispositive and between members 3 and 6 at such times as member 3 ispositive. It will thus be seen that contact member 6 will be, for agreat portion of the time, in contact with points of positive potentialand, accordingly, unidirectional pulsating current will flow fromcontact member 6 through load 17 to the mid point of the source 14.

If desired, the device may be so adjusted that the contact member 6 willtouch contact members 3 and 4 only at such times as the latter are ofnegative polarity, under which conditions, the direction of current flowthrough the load 17 will be reversed. Owing to the resiliency of thecontact members 3 and 4, they will remain in contact with member 6 foran appreciable length of time.

If desired, member 5 may be in electrical connection with contact member6 and current be led to the latter at point 7 rather than through aspring such as 15. This system of connections is shown in Fig. 3.

WVhat I claim is:

1.- A mechanical rectifier comprising a pair of fixed contact membersmounted upon a base and insulated therefrom, a rotatable cam. apivotally mounted, oscillatory member of Y-shape, both arms of whichengage the cam, and a contact member carried by an extension of saidoscillatory member and vibratory between the two fixed contact members.

2. A mechanical rectifier comprising a pair of fixed contact membersmounted upon a base and insulated therefrom, a rotatable cam, apivotally mounted, oscillatory member of Y-shape engaging the rotatablecam on substantially opposite sides thereof, a

' contact member carried by an extension of said oscillatory member andvibratory be- 4 tween the two fixed contact members, and

connected to each terminal of said source, a, frequency of thealternating current source. movable contact member between said fixed Intestimony whereof, I have hereunto 10 contact members, and meanscomprising a subscribed my name this 23rd day of Mar. cam engaging thesupport of the movable 1914.

contact member and a synchronous motor CHARLES LE G. FORTESCUE.operating from said source and driving said Witnesses:

cam, whereby said movable contact member \V. M. MCCONAHEY,

is caused to vibrate in synchronism with the 1 B. B. HINES.

